Exhumation and uplift coupled with precipitation along the western Dead Sea Rift margin
Exhumation and uplift coupled with precipitation along the western Dead Sea Rift margin
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死海裂谷边缘西部折返和抬升以及降水
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
L. Benedetti
中科院分区：
文献类型：
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作者：
U. Ryb;A. Matmon;I. Haviv;L. Benedetti
以化学风化为主的碳酸盐地形的剥蚀可以被视为雨量计代理，因为随着时间的推移溶解损失的质量与时间积分降水量成正比。因此，碳酸盐地貌的剥蚀历史可以提供古降水数据，并揭示气候、剥蚀和构造隆升之间的相互作用。我们应用这种方法来限制死海裂谷 (DSR) 西缘沿线 10 4 – 10 7 年的平均降水量，该边缘主要由碳酸盐岩覆盖，并沿其轴线及其迎风侧和背风侧之间保持从地中海到超级干旱的气候梯度。总剥蚀量（来自土仑纪基准面）、剥蚀率计算（来自原位 36 Cl 测量）和当前年平均降水量之间的比较表明：（1）总剥蚀量与剥蚀率相关，并且两者都与降水量相关；（2）在该山脉的寿命期间（10-20 m.y.），整个山脉的有效降水梯度平均比目前高至少 40%。沿着~450公里长的范围，剥蚀梯度可能被均衡抬升所补偿。我们认为，沿着 DSR 边缘西部，可能在其他碳酸盐地形中，降水（降水阈值约为 ∼1000 mm yr –1 ）控制着长期剥蚀率和随后的补偿性抬升。
Denudation of carbonate terrains dominated by chemical weathering can be treated as a rain gauge proxy, because the mass lost by dissolution over time is proportional to the time-integrated precipitation. Therefore, the denudation history of carbonate landscapes may provide paleoprecipitation data and shed light on the interactions between climate, denudation, and tectonic uplift. We apply this approach to constrain 10 4 –10 7 yr average precipitation along the western Dead Sea Rift (DSR) margin, which is underlain predominantly by carbonate rocks and maintains a climatic gradient from Mediterranean to hyperarid along its axis and between its windward and leeward flanks. The comparison between total denudation (from a Turonian datum), denudation rate calculations (from in-situ 36 Cl measurements), and present-day mean annual precipitation shows that (1) total denudation correlates with denudation rates and both correlate with precipitation, and (2) over the lifetime of the range (10–20 m.y.), the effective precipitation gradient across the range was higher than at present by at least 40% on average. Along the ∼450-km-long range, the denudation gradient is probably compensated by isostatic uplift. We suggest that along the western DSR margin, and possibly in other carbonate terrains, precipitation (to a threshold precipitation of ∼1000 mm yr –1 ) controls the long-term denudation rate and the subsequent compensating uplift.